Fig. 1 · Ab to C

interval

A♭ major third

A♭lowerCupperM34 half steps

Four half steps. The interval that makes a triad major.

On the keyboard

CAb
Fig. 2

What is true of it

A♭ up a major third is C: 4 half steps, and 3 letters counting both ends.

Turn it upside down — put the A♭ on top — and it becomes a minor sixth. The two numbers always add to nine, and the two sizes to twelve.

It is a imperfect consonance.

Every interval on A♭

A♭ → B♭♭minor second · dissonanceA♭ → B♭major second · dissonanceA♭ → C♭minor third · imperfect consonanceA♭ → D♭perfect fourth · perfect consonanceA♭ → Daugmented fourth · dissonanceA♭ → E♭♭diminished fifth · dissonanceA♭ → E♭perfect fifth · perfect consonanceA♭ → F♭minor sixth · imperfect consonanceA♭ → Fmajor sixth · imperfect consonanceA♭ → G♭minor seventh · dissonanceA♭ → Gmajor seventh · dissonance

C M3C♯ M3D♭ M3D M3D♯ M3E♭ M3E M3F M3all 204